1. Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, Canada H3A 1B1
2. Hong Kong Cetacean Research Project, Flat C 22/F., Block 13, Sceneway Garden, Lam Tin, Kowloon, Hong Kong
3. Department of Marine Biology, Texas A&M University at Galveston, 200 SeaWolf Pkwy, Galveston, TX 77553, USA